This is the year where the Marvel Universe truly becomes a Universe. It's 'announced' more or less, with the big FF/Avengers/Hulk fight in FF #25-26, and then goes on with a ton of guest appearances and very tight continuity across books. This is what this whole site is about, and this is where it really starts to happen.

If Paste Pot Pete gets an early parole because he helped the Avengers dissolve Baron Zemo's Adhesive X, then when he next shows up to bother the Human Torch, he talks about it. It's now a part of his history. This sounds like a small thing, but it's one of the main things that made Marvel something special in the comic book industry in the mid-60s (the other thing was their 'real life' characterizations of their characters). The very fact that the Avengers would think to call up a super villain from another comic book to ask for help is a huge deal.

Creator notes: This is still mainly a Lee/Kirby/Dikto show, with Don Heck on Iron Man and Dick Ayers and others occasionally popping up in a fill-in capacity. Lots of continuity inserts: Busiek's Untold Tales of Spider-Man is still going strong, and the second part of Iron Man: The Iron Age takes place here, although it's not as great as the first one. Mark Waid's Captain America: Sentinel of Liberty provides a very nice look at Cap's adjustment to the modern world. Frank Miller's Man Without Fear mini provides a great origin for Daredevil, and a -1 Flashback book for Electra by Peter Milligan fits in here as well.

Notable events: Some super-villain teams and partnerships form this year: the Brotherhood of Evil Mutants, the Masters of Evil, Cobra and Hyde, the Sinister Six.